1. Field of the Invention
The present invention relates to an information processing terminal, a data selection processing method, and a program.
2. Description of the Related Art
In recent years, information processing terminals that are capable of communicating with a non-contact type read/write unit (reader/writer) have come into widespread use, including mobile telephones and the like that are provided with non-contact type integrated circuit (IC) cards (hereinafter called by their generally used name “smart cards”) or smart card functions. The read/write unit and the information processing terminal utilize a magnetic field (hereinafter called the “carrier wave”) of a specific frequency, such as 13.56 MHz or the like, for communication, using the carrier wave to transmit and receive data.
The information processing terminal, such as the mobile telephone or the like that is provided with the smart card or the smart card functions, can also be driven by the magnetic field energy it receives from the read/write unit, whether or not the terminal itself has a built-in power supply. Specifically, a magnetic field can be generated by passing an electric current through a coil that is provided in and serves as a transmitting/receiving antenna for the read/write unit. When the magnetic field passes through the coil that is provided in and serves as a transmitting/receiving antenna for the information processing terminal, a voltage (hereinafter called the “induced voltage”) is generated in accordance with the magnetic flux. The induced voltage serves as the power supply for the information processing terminal.
Generally, the strength of the magnetic field that the transmitting/receiving antenna of the information processing terminal receives from the read/write unit increases as the distance between the read/write unit and the information processing terminal decreases. The induced voltage also increases accordingly.
Furthermore, the strength of the magnetic field that the transmitting/receiving antenna of the information processing terminal receives from the read/write unit decreases as the distance between the read/write unit and the information processing terminal increases. The induced voltage also decreases accordingly.
The information processing terminal, such as the mobile telephone or the like that is provided with the smart card or the smart card functions, is light and small, so the information processing terminal user (hereinafter called the “user”) can easily vary the distance between the read/write unit and the information processing terminal.
The user can also easily move the information processing terminal close to the read/write unit in a wide variety of orientations. For example, the user can move the front face of a mobile telephone close to the read/write unit, move the rear face of a mobile telephone close to the read/write unit, and the like. That is, even when the distance between the read/write unit and the information processing terminal is fixed, the distance between the transmitting/receiving antenna of the read/write unit and the transmitting/receiving antenna of the information processing terminal varies by the thickness of the information processing terminal, depending on whether the front face is closer to the read/write unit or the rear face is closer to the read/write unit.
Moreover, in a case where the face on the side of the information processing terminal where the transmitting/receiving antenna is installed does not face the read/write unit, there is a strong possibility that the operation of another element, such as a circuit board or the like that is provided in the information processing terminal, will create eddy current loss and make data communications impossible.
To solve these problems, attempts have been made to install a plurality of coils to serve as transmitting/receiving antennas in the information processing terminal in an effort to increase the efficiency of data reception in relation to electric power in the information processing terminal and to stabilize the communications between the read/write unit and the information processing terminal.
Furthermore, as the miniaturization of semiconductors has progressed, the functions that are included in the information processing terminals have increased dramatically. Attempts have even been made to add the functions of the read/write unit to the information processing terminals that are provided with smart card functions.
An example of a technology for installing the plurality of coils to serve as transmitting/receiving antennas in the information processing terminal is disclosed in Japanese Patent Application Publication No. JP-A-2006-13777. An example of a technology for providing the functions of the read/write unit in the information processing terminal is disclosed in Japanese Patent Application Publication No. JP-A-2005-92352.